iMac with Radeon HD 4850 vs others

Thanks to Tom Dahl, a member of MacRumors forum, I have some 4850 X-Plane benchmark results (vs other GPUs) to share....

Running X-Plane Demo 9.22 benchmark using a recorded 1 min flight of the X-15 dropped from a bomber, it produces results for three phases. Averaging these, we get the following for the iMac 3.08 with three different GPUs ....
GeForce 8800 GS = 70 fps
GeForce 130 GT = 71 fps
Radeon HD 4850 = 101 fps

It appears from the Mac Pro numbers that X-Plane "favors" ATI GPUs so don't draw too much from this. Hopefully I'll have results for a whole spectrum of 3D Gaming benchmarks to share soon as I expect our iMac with 4850 to arrive this week.

Hmm. It's interesting that the iMac's 8800GS and GT130 can beat the Mac Pro's 8800GT significantly considering the 8800GT should be faster than either of them. Is this with the newer beta drivers you received in which case there would appear to still be problems.

I've probably mentioned this to death in other threads, but it'd be great if you could find out the clock speeds and other specs of the various GPUs.

Hmm. It's interesting that the iMac's 8800GS and GT130 can beat the Mac Pro's 8800GT significantly considering the 8800GT should be faster than either of them. Is this with the newer beta drivers you received in which case there would appear to still be problems.

I've probably mentioned this to death in other threads, but it'd be great if you could find out the clock speeds and other specs of the various GPUs.

I'm working on that. I may have to boot Windows XP or Vista to check the clock speeds ATI Tools once our iMac with 4850 arrives.
I'm also trying to find out if it's a mobile version of the 4850 or a true desktop version. My guess is that it's more like the mobile version for lower power requirements and lower heat generation inside the iMac.

As for ATI GPU dominance with X-Plane, I made it sound like the X-Plane people favor ATI. That's not the case. A year ago, the nVidia GPUs were being promoted by the X-Plane website as the best GPU for their game. ATI contacted them to see what they could do to make their cards run better. What you are seeing in my numbers are the fruits of ATI's labors.

BTW, if any of you have an older iMac or 3GHz Woodcrest or Clovertown Mac Pro with any graphics card, I'd like to get your X-plane results to compare to the new iMacs. Email me for test procedures and test flight sequence using the X-Plane 922 Demo.

Still waiting for my iMac with 4850 but one of my "remote mad scientists" sent me his CoD4 results at 1920x1200 High:
2.93 iMac with 4850 = 61 fps
3.06 iMac with 130GT = 38 fps

That's a 60% advantage - - similar to what we saw with X-Plane.
And nipping at the heels of the Mac Pro 2.93 with 4870 (64 fps).

That's good performance from the iMac especially as I imagined the mobile 4850 wouldn't be as strong as the 4870.

Is that Mac Pro result quoted from a Quad or 8-Core? I only see the 8-Core listed on your site and that is showing 60 fps - there is a 3.2GHz Harpertown showing 64 fps?

It seems like COD4 cares most of all about processor clock speed - this makes it hard to guess how well a 2.26GHz 8-Core model will hold up for gaming over the next few years (I was just about to go for it over a quad from the video encoding/multitasking advantages).

COD4 seems to be the one game where the numbers matter - with the other games the difference probably won't give a different experience.

Rob starting to see reports of users having problems with the new iMacs configured with the 4850 GPU having multiple freezes. Check out the following.

It's odd. Some are having problems and some are not.
There's a constructive thread on the MacRumors Forum where owners are trying to zero in on the cause:http://forums.macrum...ad.php?t=688393

Two theories are...
... it's the AirPort firmware version (disable AirPort an crashes stop, at least in some reports)
... it's a bad batch of Radeon 4850s (since it does not seem to happen on GeForce equipped iMacs but does on some with Radeon 4850s)

Just as a FYI, Apple has released a firmware update for the 2009 iMacs with the ATI 4850 GPU. The firmware update is available by running software update. From reports I have read it seems to have taken care of the freezes users where having.

Our iMac 3.06 with Radeon HD 4850 (finally) arrived as of Friday, May 8th. I ran our regular suite of 3D Games at 1920x1200 High Quality. Our graphs show how it compares to various other iMac GPUs as well as some "comparable" Mac Pro GPUs:http://www.barefeats.com/imac09.html

As for freezing, we haven't had seen that behavior. I noticed the May 2nd firmware upgrade for the iMac was already installed in our unit when it arrived.